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By Jim Gebhardt

Douglas W. Fuerstenau (DWF) grew up on a farm and in several small communities in rural South Dakota during the depression years, where he learned the value of hard work. Working hard can produce results but being clever and hardworking will give you a bright future. In his later school years, Fuerstenau’s family moved to Rapid City where his intellectual curiosity and capacity helped him graduate with a B.S. in Metallurgical Engineering from the South Dakota School of Mines and Technology in 1949. His technical interests led to graduate studies and completion of a master’s degree from the Montana School of Mines in 1950 and Sc.D. degree from the Massachusetts Institute of Technology (MIT) in 1953.

By Egons R. Podnieks, Wallace W. Roepke

Mining technology to utilize vital lunar resources will be required for any commitment to permanent lunar basing. Lunar mining must be viewed both as a major supporting element for space resource commercialization and for creation of human settlements on lunar and planetary surfaces to support long-range space exploration. The Apollo missions to the lunar surface and results from fundamental research on analogue lunar rocks by the Bureau of Mines, and others, have provided the initial data for developing lunar mining technology. The multi-disciplinary research projected in this paper outlines the scientific and engineering needs to realize the lunar mining goals.

Jan 1, 1990

By James J. Meadows, Jason D. Pampena, Emanuele G. Cauda, Lauren G. Chubb

Respirable crystalline silica (RCS) found in dust generated by various mining processes is an important occupational hazard in the underground coal-mining industry. Exposure can lead to disabling and incurable diseases, including coal workers’ pneumoconiosis (CWP), silicosis and lung cancer [1,2]. Clusters of rapidly progressive CWP have been observed in the Appalachian regions of eastern Kentucky and southwestern Virginia, and recent cases have been generally more severe and showing more rapid progression. CWP is approximately four times as common among long-tenured underground coal miners in central Appalachia than long-tenured underground miners in the rest of the United States, and 20.6 percent of long-tenured underground miners in central Appalachia were suffering from the disease as of 2017.

By C. Vasilescu

Phytotechnologies use plants to remediate various media impacted with different types of contaminants. These technologies can be implemented either in situ or ex situ. The affected media in which phytotechnologies can be applied include soil, sediments, groundwater and surface water. They are best applied at sites with shallow contamination of organic, nutrient, or metal pollutants that are amenable to one of five treatment options: phytoextraction, phytotrans-formation, rhizosphere, bioremediation, phyto-stabilization or rhizofiltration. Phytoremediation can be used along or, in some cases, in place of mechanical cleanup methods. Phytoremediation can be used to clean up metals, pesticides, solvents, explosives, crude oil, polycyclic aromatic hydrocarbons and landfill leachates.

Jan 1, 2006

By Wolfgang Pietsch

Roller presses were first invented in the middle of the 19th century, for the economical size enlargement of coal fines as fuels. Coal briquettes became quickly accepted for industrial and domestic use giving rise to a large and sucessful industry, particularly in Europe, Japan, and North America. When, towards the middle of the 20th century, coal was more and more replaced by other energy sources, such as electricity, gas, and oil, roller press manufacturers searched for alternate applications of this equipment. In addition to contemporary coal briquetting, in fields such as smokeless fuel and form-coke, it was found that redesigned and modernized roller presses, which are now capable of exerting high forces, are versatile machines for many tasks in mineral processing. Today they are used for: - the "classic" pressure agglomeration and - the "new" high pressure comminution. In pressure agglomeration, the characteristics of fine minerals are improved by forming briquettes or granulated products from compacts. During size enlargement with roller presses briquettes are directly obtained while granular materials are produced by crushing and sizing of compacted sheets. The processes are carried-out essentially dry and often do not require binders other than those inherently contained in the feed and "activated" by the high forces and/or elevated feed temperatures (e.g. hot briquetting). Therefore, no foreign materials (impurities) are added. Another advantage of the technology is, that wide particle size distributions are acceptable or desirable as feed materials, including millimeter or even centimeter sized particles. Plastic particles deform and brittle materials are crushed during pressure agglomeration. A relatively new application of roller presses in mineral processing is the utilization of the crushing effect when brittle materials pass the nip area between the rollers. It was found that this crushing mechanism is very efficient thus saving energy, particularly in grinding circuits handling large capacities. The paper introduces the fundamentals of the process and describes the design as well as applications of modern roller presses in mineral processing.

Jan 1, 1995

By S. S. Peng

This paper presents a computer program package for predicting surface movement and deformation caused by under-ground coal extractions. It is capable of: predicting final surface movement and deformation over underground openings; predicting dynamic surface movement and deformation process associated with underground lingual mining operations; processing and bookkeeping subsidence survey data; recommending subsidence parameters for those new coal mines where no subsidence data are available; and deducting subsidence parameters from collected subsidence data.

Jan 1, 1986

By T. J. De Mull

The Alligator Ridge Mine is located 70 miles northwest of Ely in White Pine County, Nevada. Development of the mine began in the late 1970's as a joint venture between Amselco Minerals, Inc. and Occidental Minerals Corporation, with Amselco as the operating partner. Early in 1983 Nerco Minerals Company acquired Occidental's share of the property. The mine and ore processing facility have operated at capacity since 1981 producing 680,000 tonnes of ore and 1,900 kg of gold per year. The gold ore deposits at Alligator Ridge consist of disseminated micron-size gold particles in a silicified siltstone matrix. The deposit comprises three separate but adjacent areas of mineralization that are designated as Vantage 1, Vantage 2, and Vantage 3 after the name of the basin in which the deposits lie.

Jan 1, 1983

By Setareh Afrouz, Emily Sarver, Cigdem Keles

The resurgence of severe lung disease among US coal miners since the mid-1990s has led to efforts to better characterize and monitor respirable dust exposures, particularly focusing on mineral constituents from rock strata surrounding the coal. A rapid analysis method for silica (quartz) mass using direct-on-filter Fourier transform infrared (FTIR) spectroscopy has been developed, which can also estimate kaolinite, a primary silicate mineral in many coal mines.

Feb 24, 2022

By Elham Najafi, Sina Ghassa, Ata Akcil, Hadi Abdollahi, Sandeep Panda, Zohreh Boroumand

Bioleaching is an environmental friendly process that has gained much interest for the production of metals from metal-bearing wastes or materials. The process decreases carbon footprint by reducing consumption of fossil fuels. Iron is a key factor in acidophilic iron-oxidizing bacteria’s activity, which is used extensively in the bioleaching of sulfide minerals. In the present study, the effect of different iron sources is investigated on sphalerite (ZnS) bioleaching. For this purpose, the effects of FeSO4  .7H2O, Fe2(SO4  )3 and FeS2 (pyrite) were studied on bacterial activity, and zinc (Zn), lead (Pb), cadmium (Cd) and arsenic (As) dissolutions were monitored from a ZnS concentrate. Under optimum conditions, the dissolutions of Zn, Pb, Cd and As were found to be 39.8, 0.1. 0.03 and 10 percent, respectively, in 25 days.

By S. Maurigiannakis

In an effort to promote sustainability in the construction industry, the natural decorative stones that cover large external areas of buildings may be replaced with artificial stones. In this paper the physical and mechanical properties of artificial decorative stones are presented and are critically compared with corresponding natural stones. To test suitability for various applications, artificial stone specimens were subjected to weathering testing (freezing-thaw cycles in a climatic chamber). Mechanical characterization of these specimens was based on uniaxial compressive testing as well as non-destructive ultrasonic testing. Preliminary results show that artificial stones can replace natural stones, thus creating a sustainable development option for the construction industry.

Jan 1, 2003

By B. K. Mishra, A. Datta

Estimating the power draw of a ball mill is of great importance from both operational and control standpoints. There are many factors that affect the power draw, and its prediction is particularly difficult in an operating plant. The important factors that affect power draw are the mill dimensions and operating parameters. Although mill dimensions remain the same for any given mill, the operational factors, such as ball load, mill filling and mill speed, may vary. This makes the modeling effort extremely cumbersome. It is for this reason that an artificial neural network is considered for the development of a black-box-type model to predict power draw. In this work, a total of 48 sets of plant data are used. Using these data, a neural network is built and trained. The trained network is used to predict power that is found to be in good agreement with operating mill power for many situations. In addition, the results of simulations are also com- pared to those obtained from a discrete-element method- based power-draw model.

Jan 1, 2000

By J. K. Horbaczewski

The reclamation of an open dragline pit (Pond A3P-2) at the Gibbons Creek lignite mine in east-central Texas required neutralization of acid mine pit water. At the start of treatment with hydrated lime (Ca(OH)2) on March 28, 2000, the pond had partially filled with 913,000 m3 (740 acre ft) of pH 4.9 water. Another 666,600 m3 (540 acre ft) of pH 3.3 water was pumped in from an adjacent pit (PitA3P- 1). By the end of the project (July 5, 2000), a combined volume of 1,579,000m3(1,280ac-ft or 417milliongal) in PondA3P-2 had been successfully treated to pH 8.2 with 431 t (475 st) of lime. This was two to three times more neutralizer than laboratory trials and detailed chemical titration had predicted. The main reasons for the difference are thought to be the inadequate representation in a laboratory setting of some of the chemical reactions that occurred in the field, including incomplete mixing of reactants, reactions with clay minerals in the pit walls, the kinetics of biologically-mediated reactions and the kinetics of aluminum oxyhydroxide polymerization (aging).

Jan 1, 2002

By David Court, Rab Brown

The paper discusses the work in progress on the construction of the extension of the High Speed Rail line from the Channel Tunnel into the centre of London UK known as the “Channel Tunnel Rail Link” (CTRL), and particularly on contract 250 which involves the construction of two 5.3Km tunnels 7.15m diameter constructed with two EPB convertible tunnelling machines underneath the densely populated area of East London. In addition the paper will look at an innovative Alliance that has been formed between the Contractors and the Client’s Engineer involved in the construction of the London Tunnel Contracts

Jan 1, 2003

By Dennis R. Twining

Recently a mining analyst for a major bank called me to say that during his travels he had encountered an electric utility interested in a new uranium supply. Since we produce uranium as a by-product of phosphate operations rather than as a primary product, he assumed we simply sold our output in the spot market and that a new prospective purchaser would be of interest to us. This assumption was incorrect; the uranium had already been sold on a long term basis at terms more favorable than the currently depressed spot market. From the outset our approach to the marketing of uranium was based on the principle that by-product marketing is not unlike primary product marketing. This was particularly appropriate in the case of uranium, as we were planning a considerable technical and capital commitment to a new business. This illustrates: that the fundamental principle in by-product marketing is to follow a primary product strategy; that the terms "by-product" or "co-product" are creations of accountants; that they have no place in marketing decisions! Traditionally, the term "by-product" has implied that only a secondary marketing effort is required. Recent history has contradicted that view by demonstrating that by-product values can have marked impact on a mine's revenues and costs. In fact, by-product values can spell the difference between success and failure.

Jan 1, 1983

By Erwin Riyanto, Roy William, Karl Llewellyn

The Deep Mill Level Zone (DMLZ) mine is currently one of the deepest block cave mines in the world. The rock mass is heavily veined with little to no joints and faults are usually healed cohesive structures leading to difficult cave mining conditions. The caving process is improved if the rock mass contains fractures with sufficient density that it will cave by gravity as undercutting progresses. Hydraulic fracturing (HF) has been used to create fractures around the cave to improve mining. A seismic monitoring system has been used in DMLZ since the start of mining. Therefore, the seismic activities before, during and after HF can be monitored. Shear wave splitting is a process used to study the impacts of HF on the rock mass. This process involves the measurement of travel times from splitting shear waves after seismic events and using this to define the anisotropy within the rock mass and subsequently fracture density. This paper sets out the methodology for carrying out the interpretation of the shear wave splitting process using seismic data from the fracked cave crown and abutments along with an overview of the benefits to cave mining as result.

Apr 26, 2022

Traditional finance theory recommends discounted cash flow (DCF) analysis as the tool to value mineral properties. Yet, the calculated values by this method are usually lower than the market value. Finance theory also advises us to develop an undeveloped project immediately if its net present value is positive. Most projects are, however, only developed when the economics are highly favorable. This paper uses insights from option-pricing theory to explain these divergences between market behavior and finance theory and presents simple modifications to discounted cash flow analyses that will lead them to produce correct valuation and development timing advice.

Jan 1, 1999

By Taghi Sherizadeh, Kutay E. Karadeniz, Dogukan Guner, Samuel Nowak

Mine explosions are one of the most concerning risks related to underground coal mining, as a single gas explosion can cause injuries and fatalities among miners. Underground infrastructure seals and build-in-place (BIP) refuge alternatives (RAs) are employed to isolate an area from active workings to mitigate coal mining-related accident risks. They are designed to withstand blast pressures from a possible accidental detonation of the contained gas or a coal dust explosion. Crosscut seals and BIP RAs, typically consisting of steel-reinforced concrete, are prone to strong convergence and have a significant leakage potential due to high convergence damage near mined-out areas. The roof-to-floor convergence can change the structural integrity of these structures, and altered structural integrity can lead to less explosion resistance capability. Hence, a thorough analysis is needed to further understand their explosion response under various strata conditions.

Jul 1, 2023

By Long An, Chao Wu, Yuanhui Li, Xing Sun, Shuai Xu, Changyu Jin

Stage open stope mining (SOSM) maintains the stability of excavation openings by leaving a large number of rib pillars. Affected by the strong unloading due to stage mining and the low width-to-height (w/h) ratio of the pillars remaining, large-scale destabilization disasters of rib pillars or excavation openings easily occur when the distribution of ground stress or the size of rib pillars is unreasonable. In view of these problems, a physical SOSM model test was carried out based on an underground metal mine in the city of Chifeng in China, revealing the deformation and failure characteristics of the SOSM pillar group by overloading.

Jul 1, 2023

By Amanda Powers, Brian Glynn, Robert Sauceda, Daniel Huffines, Mike Garbeth

This paper will review the evaluation performed for the Cottonwood & Hackberry Creek Wastewater Interceptor Improvements Project to replace two separate aging and undersized interceptor sewers by either open cut construction or trenchless construction methods. A case study will be discussed for the utilization of microtunneling to avoid a deep open cut excavation within a landscaped roadway median to construct nearly a mile of new 60-inch interceptor sewer in an urban area adjacent to an environmentally sensitive riverine area, while minimizing the permitting and environmental impacts of construction, and minimizing the impacts to residents and vehicular trafc and restoration reuirements.

Jun 23, 2024

By F. L. Pirkle

A heavy mineral deposit about 1.6 km (1 mile) in length, 0.13 km (0.08 mile) in width and averaging about 3 m (10 ft) in thickness is exposed approximately 130 km (80 miles) east of Denver, along Interstate 70, in Elbert county, CO near the town of Limon. The deposit is exposed in a geomorphic feature known locally as Titanium ridge. The dominant heavy minerals, accounting for about 70% of the total heavy-mineral suite by weight, are ilmenite, garnet and zircon. The mineralized zone appears in a series of visually interpretable facies that are stacked vertically and represent subtidal, forebeach, backbeach, washover fan and aeolian depositional environments. These paleoenvironments are analogous to depositional environments represented by a modern heavy-mineral bearing facies tract on St. Catherines Island, Ga. Thus, Titanium ridge provides evidence that heavy-mineral accumulation models for late cenozoic deposits in the Georgia and Florida coastal plains are applicable to heavy-mineral deposits of the Western Interior subsurface and, by implication, the Western Interior Seaway, extending from Mexico to the Canadian Arctic.

Jan 1, 2012